Cancer chemoprevention and treatment by natural compounds has emerged as a promising and pragmatic approach to reduce the burden of cancer. Natural compounds has contributed for more than 60% of prevailing chemotherapeutic anticancer drugs. Identification and characterization of novel natural anti-glioma compounds from Traditional Chinese Medicinal Herbs was the main goal of this book. Unlike pharmaceutical drugs that are equally toxic to both cancer and normal cells, we have identified natural compounds which are quite toxic to cancer cells while less toxic to normal cells. Induction of apoptosis and cell cycle arrest were the major mechanisms associated with anticancer effects of these bioactive compounds. Induction of oxidative stress to a toxic threshold, which can be easily achieved in cancer cells compared to normal cells, have been found to be the major reason of selective cytotoxicity of these compounds.